The present fastener is a variation of the general type of magnetic fastener shown in U.S. Pat. Nos. 4,021,891; 4,453,294; and 5,274,889, and more particularly, an improvement of the magnetic slide type fasteners shown in U.S. Pat. Nos. 5,199,138; 5,253,394; 5,377,392; 5,515,581; and 5,572,772. The magnetic fasteners disclosed in U.S. Pat. Nos. 4,021,891; 4,453,299; and 5,274,889 include cooperating female and male member assemblies. The female member typically includes a permanent magnet, a ferromagnetic member at one of its poles, and appropriate cover means for protectively enclosing the permanent magnet and controlling the magnetic flux paths. The male member assembly includes a cooperating ferromagnetic member which upon proximity between the two members will be magnetically attracted to the female member assembly to provide for a proper positioning and centering of the interengaged male and female member assemblies. The permanent magnet of the female assembly includes a central opening for receiving, and appropriately positioning, a projecting ferromagnetic portion of the male member. The particular selection and configuration of the ferromagnetic and nonferromagnetic portions of such magnetic assemblies have varied in accordance with the particular requirements and design of their intended applications. Although widely successful, fasteners of this type are maintained in their closed position solely by magnetic attraction.
It has been previously proposed in U.S. Pat. Nos. 5,199,138; 5,253,394; 5,377,392; 5,515,581; and 5,572,772 to provide for a sliding manually defeatable mechanical locking engagement between the male and female members, in addition to their magnetic attraction. Those magnetic fasteners have generally included a permanent magnet projecting outward of the male assembly having a detent for engaging a sliding ferromagnetic plate, or plates, within the female assembly. The male assembly may then typically be attached to the body of a handbag. Since the permanent magnet of the male assembly is not shielded, such fasteners may disadvantageously cause some erasure of magnetic encoding on credit cards which are typically stored in handbags, or other articles intended to utilize such magnetic fasteners. Further, the attached magnetic closures disclosed therein are relatively complex, large, and utilize a multiplicity of parts resulting in manufacturing complexities and high costs, limiting their commercial utility. The excessive size and other disadvantages of the magnetic fasteners disclosed in U.S. Pat. Nos. 5,199,138; 5,253,394; and 5,377,392 is reviewed in U.S. Pat. No. 5,572,772, of the same inventor. These previously proposed magnetic slide fasteners all utilized a rectangular forwarding projecting male member and a similarly configured female aperture, requiring precise alignment in the installation of the two assemblies on the handbag. Further, the female assemblies shown in U.S. Pat. Nos. 5,199,138; 5,293,394; 5,377,392; and 5,572,772 could only be secured to the lip of a handbag flap, tending to limit their practical utilization.